Читать книгу Surgical Critical Care and Emergency Surgery - Группа авторов - Страница 16

Rathnayaka M. K. Gunasingha, MD1, Patrick Benoit, DO1, and Matthew J. Bradley, MD2

1 Walter Reed National Military Medical Center, Bethesda, MD, USA

2 Uniformed Services University of the Health Sciences, Program Director General Surgery Residency, Walter Reed National Military Medical Center, Bethesda, MD, USA

1 A 28‐year‐old man is found by police obtunded with a respiratory rate of four per minute in a local park. He was administered naloxone in the field and transported to the hospital. On arrival, he continues to be lethargic with a blood pressure of 90/54 mm Hg, heart rate of 103/min, respiratory rate of 16/min, and temperature of 101.1o F. Physical exam reveals a 3cm × 3cm area of erythema, fluctuance, and induration in his left antecubital fossa as well as tender nodules on his fingertips. Auscultation of his chest reveals a blowing diastolic murmur. A transthoracic echocardiogram is negative for any signs of endocarditis. The next steps in the management of this patient including blood cultures, fluid resuscitation, and I & D of abscess should include:Transesophageal echocardiography, initiation of vancomycinTransesophageal echocardiography, initiation of vancomycin and piperacillin‐tazobactamTransesophageal echocardiographyMetronidazole and piperacillin‐tazobactamVancomycin and metronidazoleThis patient has 3 minor Modified Duke Criteria – (1) intravenous drug use, (2) fever > 100.4°F, and (3) Osler’s nodes – that indicate possible endocarditis. Intravenous drug use is a risk factor for acquisition of infective endocarditis. The patient should receive a transesophageal echo (TEE) to evaluate his cardiac valves even though the transthoracic echocardiogram was negative as TEE is more sensitive for cardiac vegetations. Staphylococcus aureus is the most common organism that causes infective endocarditis, followed by Viridans group Streptococci, coagulase‐negative Staphylococci, Enterococcus species, and Streptococcus bovis. Antibiotics should be started immediately after drawing blood cultures and should be broad to include MRSA coverage. Answer B is the correct choice as it provides broad‐spectrum coverage as well as the TEE that is needed after a negative TTE in this patient whose presentation is suspicious for infective endocarditis. Answer A adequately covers for MRSA, but without a known causative organism, more broad‐spectrum antibiotics should be initiated. Answer C is incorrect as it is critical that in cases of suspected endocarditis and sepsis that antibiotics be administered immediately after presentation. Answer D does not adequately cover against MRSA and is therefore incorrect. Answer E does not adequately cover gram‐negative bacteria and is therefore inadequate as initial therapy for this patient. It is a strong recommendation to consult Infectious Disease to determine the optimal empirical antibiotic treatment. The fluctuance and induration at the patient’s antecubital fossa indicate an abscess and must be drained as part of the treatment.References for images:Modified duke criteriaPathological criteriaPositive histology or culture from pathological material obtained at autopsy or cardiac surgeryMajor criteriaTwo positive blood cultures with typical organismPersistent bacteremiaPositive serology for CoxiellaPositive echocardiogramVegetation ORAbscess ORNew regurgitation ORDehiscence of prosthetic valvesMinor criteriaPredisposing heart disease or IVDAFever > 38%Immunological phenomenaVascular phenomenaMicrobiological evidence not fitting major criteriaAnswer: BGalindo R . Osler’s nodes on hand. https://commons.wikimedia.org/wiki/File:Osler_Nodules_Hand.jpg. Published 2010. Accessed July 26, 2021.Galindo R . Osler spots on foot. https://commons.wikimedia.org/wiki/File:Osler_Spots_foot.jpg. Published 2010. Accessed July 26, 2021Baddour LM, Wilson WR, Bayer AS, et al. Infective endocarditis in adults: diagnosis, antimicrobial therapy, and management of complications: a scientific statement for healthcare professionals from the American Heart Association. Circulation. 2015; 132(15):1435–1486. doi:10.1161/CIR.0000000000000296Vogkou CT, Vlachogiannis NI, Palaiodimos L, et al. The causative agents in infective endocarditis: a systematic review comprising 33,214 cases. Eur J Clin Microbiol Infect Dis. 2016; 35(8):1227–1245. doi:10.1007/s10096‐016‐2660‐6Wang A, Gaca JG, Chu VH . Management considerations in infective endocarditis: a review. JAMA ‐ J Am Med Assoc. 2018; 320(1):72–83. doi:10.1001/jama.2018.75961.Miller SE, Maragakis LL . Central line‐associated bloodstream infection prevention. Curr Opin Infect Dis. 2012; 25(4):412–422. doi:10.1097/QCO.0b013e328355e4daLatif A, Halim MS, Pronovost PJ . Eliminating infections in the ICU: CLABSI. Curr Infect Dis Rep. 2015; 17(7). doi:10.1007/s11908‐015‐0491‐8Noto MJ, Domenico HJ, Byrne DW, et al. Chlorhexidine bathing and health care‐associated infections: a randomized clinical trial. JAMA ‐ J Am Med Assoc. 2015; 313(4):369–378. doi:10.1001/jama.2014.18400

2 A 65‐year‐old man was admitted with acute pancreatitis and has been stable with intermittent tachycardia on the floor since his admission 2 days ago. Admission CT scan of the abdomen and pelvis showed edema and fat stranding around his pancreas. On the third day, he was noted to be more tachycardic, febrile with an increase of his leukocytosis. An interval CT scan demonstrates hypoattenuation of the pancreas, a large peri‐pancreatic retroperitoneal fluid collection with air and surrounding fat stranding. The next best course of treatment is:Start antibiotics with piperacillin‐tazobactam.Start antibiotics and percutaneously drain the collection.Start antibiotics and surgery for emergent necrosectomy.Start antifungals and percutaneously drain the collection.Continue current treatment with IV fluid resuscitation.This patient has infected necrotizing pancreatitis based on the physiologic and laboratory changes and new findings on CT scan. Broad‐spectrum antibiotics should be started since the fluid collection appears to be infected on clinical exam and on CT scan. In general, there is no indication to start antibiotics in necrotizing pancreatitis unless there is a culture‐proven infection or a strong suspicion for infection (gas in collection, sepsis, and clinical deterioration). Prophylactic antibiotics should not be used for sterile necrosis. For infected pancreatic necrosis, a multicenter trial showed that a minimally invasive step‐up approach (percutaneous drainage followed by minimal invasive retroperitoneal necrosectomy if needed) reduced major complications and death when compared to open necrosectomy. Answer A is incorrect because patient has indications for the need of drainage of the fluid collection. Answer C is not optimal as necrosectomy is now suggested to be reserved for failure of a step approach method. Answer D is incorrect because antifungals are not yet indicated. Answer E is incorrect because there is evidence of infection.Answer: BDa Costa DW, Boerma D, Van Santvoort HC, et al. Staged multidisciplinary step‐up management for necrotizing pancreatitis. Br J Surg. 2014; 101(1). doi:10.1002/bjs.9346Baron TH, DiMaio CJ, Wang AY, et al. American Gastroenterological Association Clinical Practice Update: Management of Pancreatic Necrosis. Gastroenterology. 2020; 158(1):67–75.e1. doi:10.1053/j.gastro.2019.07.064van Santvoort HC, Besselink MG, Bakker OJ, et al. A step‐up approach or open necrosectomy for necrotizing pancreatitis. N Engl J Med. 2010; 362(16):1491–1502. doi:10.1056/nejmoa0908821

3 A 68‐year‐old woman was injured in MVC and had exploratory laparotomy, small bowel resection, and splenectomy. She is now three weeks post‐operative, and she has developed copious green fluid extruding from a newly opened wound on the superior aspect of her incision. Her abdomen is soft but exquisitely tender to palpation around the wound. A CT scan of the abdomen with oral contrast shows extravasation of the contrast through the abdominal wall. All of the following are important and necessary in the initial management of an enterocutaneous fistula except:Treatment and control of sepsisFluid resuscitationElectrolyte repletionEffluent control and wound careOral toleration of dietThis patient has an enterocutaneous fistula, a very morbid complication after open surgery. Mortality is associated with sepsis, malnutrition, and fluid and electrolyte disturbances. It is important to control and treat sepsis as well as resuscitate the patient first. Effluent control and wound care are necessary to control output and prevent worsening and infection of any soft tissue wound. Nutrition is important for successful management of an EC fistula and can be a combination of enteral and parenteral, depending on nutritional needs and characteristics of the fistula. Oral toleration is not important initially and definitely not necessary. Characteristics of the fistula should be used to determine the appropriate nutrition source.Answer: EEvenson AR, Fischer JE . Current management of enterocutaneous fistula. J Gastrointest Surg. 2006; 10(3):455–464. doi:10.1016/j.gassur.2005.08.001Rosenthal MD, Brown CJ, Loftus TJ, et al. Nutritional management and strategies for the enterocutaneous fistula. Curr Surg Reports. 2020; 8(6):1–10. doi:10.1007/s40137‐020‐00255‐5Gribovskaja‐Rupp I, Melton GB . Enterocutaneous fistula: proven strategies and updates. Clin Colon Rectal Surg. 2016; 29(2):130–137. doi:10.1055/s‐0036‐1580732

4 A 32‐year‐old man with HIV is brought to the hospital post‐ictal after a seizure while at home. He is now complaining of a stiff neck, nausea, and a constant headache. His temperature is 102.3°F, heart rate is 98, and blood pressure is 100/58. His ophthalmic exam reveals bilateral papilledema. What are the next steps for management after blood cultures, antibiotics, and fluids?Lumbar puncture and place an ICP monitorDexamethasone and lumbar punctureDexamethasone and obtain a CT scan of headCT scan of head and place an ICP monitorDCT scan of head and mannitolThis immunocompromised patient has signs and symptoms concerning bacterial meningitis. After blood cultures and broad‐spectrum antibiotics are started, dexamethasone should be given to adult patients. A trial that evaluated outcomes in adult patients with bacterial meningitis found that negative outcomes, including death, were significantly lower in the group that received dexamethasone versus placebo; the group with streptococcus meningitis saw the most benefit. Hence, current recommendations state starting dexamethasone for any patients with possible streptococcal meningitis and continuing it only if culture results confirm the diagnosis. CT scan of the head should be obtained before a lumbar puncture since this patient has physical exam findings of elevated intracranial pressure (ICP), is immunocompromised, and had a new onset seizure within 1 week of presentation (choice A, B). There is a small (~1%) chance of herniation in adults with elevated ICP. A lumbar puncture is eventually necessary to identify the exact organism causing meningitis but is not done immediately (choice D). Mannitol may eventually be used to lower ICP prior to performing lumbar puncture. Initial empiric antimicrobial treatment for patients with suspected bacterial meningitis includes vancomycin in combination with either ceftriaxone or cefotaxime.Answer: CPredisposing factorCommon bacterial pathogensAntimicrobial therapyAge<1 monthStreptococcus agalactiae, Escherichia coli, Listeria monocytogenes, Klebsiella speciesAmpicillin plus cefotaxime or ampicillin plus an aminoglycoside1–23 monthsStreptococcus pneumoniae, Neisseria meningitidis, S. agalactiae, Haemophilus influenzae, E. coliVancomycin plus a third‐generation cephalosporina,b2–50 yearsN. meningitidis, 5. pneumoniaeVancomycin plus a third‐generation cephalosporina,b>50 yearsS. pneumoniae, N. meningitidis, L. monocytogenes, aerobic gram‐negative bacilliVancomycin plus ampicillin plus a third‐generation cephalosporina,bHead traumaBasilar skull fractureS. pneumoniae, H. influenzae, group A β‐hemolytic streptococciVancomycin plus a third‐generation cephalosporinaPenetrating traumaStaphylococcus aureus, coagulase‐negative staphylococci (especially Staphylococcus epidermidis), aerobic gram‐negative bacilli (including Pseudomonas aeruginosa)Vancomycin plus cefepime, vancomycin plus ceftazidime, or vancomycin plus meropenemPostneurosurgeryAerobic gram‐negative bacilli (including P. aeruginosa), S. aureus, coagulase‐negative staphylococci (especially S. epidermidis)Vancomycin plus cefepime, vancomycin plus ceftazidime, or vancomycin plus meropenemCSF shuntCoagulase‐negative staphylococci (especially S. epidermidis), S. aureus, aerobic gram‐negative bacilli (including P. aeruginosa), Propionibacterium acnesVancomycin plus cefepime,c vancomycin plus ceftazidime,c or vancomycin plus meropenemca Ceftriaxone or cefotaxime.b Some experts would add rifampin if dexamethasone is also given.c In infants and children, vancomycin alone is reasonable unless Gram stains reveal the presence of gram‐negative bacilli.van de Beek D, de Gans J, Spanjaard L, et al. Clinical features and prognostic factors in adults with bacterial meningitis. N Engl J Med. 2004; 351(18):1849–1859. doi:10.1056/nejmoa040845Tunkel AR, Hartman BJ, Kaplan SL, et al. Practice guidelines for the management of bacterial meningitis. Clin Infect Dis. 2004; 39(9):1267–1284. doi:10.1086/425368chart citation:Tunkel AR, Hartman BJ, Kaplan SL, et al. Practice guidelines for the management of bacterial meningitis. Clin Infect Dis. 2004; 39(9):1267–1284. doi:10.1086/425368

5 A 77‐year‐old woman is transferred to the ICU with increased work of breathing and desaturations. She was admitted to the hospital after sustaining multiple rib fractures from a ground‐level fall and was being treated for a hospital‐acquired lobar pneumonia. A new CT chest reveals a loculated pleural collection. Which of the following is not an appropriate antibiotic regimen?Gentamycin and metronidazoleVancomycin, cefepime, and metronidazoleVancomycin and piperacillin‐tazobactamVancomycin and meropenemLinezolid and piperacillin‐tazobactamThis patient has a hospital‐acquired pneumonia complicated by an empyema. Antibiotic coverage for a pleural empyema in this setting should include coverage for gram‐positive, gram‐negative, and anaerobic organisms. In high‐risk patients, coverage should also include MRSA and Pseudomonas. Aminoglycosides could possibly have poor pleural penetration and are inactivated in the setting of infection, so they are avoided as a class in treating empyema (choice A). In patients with hospital‐acquired empyema, it is important to cover for anaerobes, MRSA, and Pseudomonas. Choice B is an appropriate antibiotic regimen as broad‐spectrum coverage is present with vancomycin covering for MRSA, cefepime covering Pseudomonas, and metronidazole for anaerobic coverage. Choice C is appropriate as the piperacillin‐tazobactam covers both Pseudomonas and anaerobes in addition to the MRSA coverage with vancomycin. Choice D is appropriate as the meropenem adequately covers Pseudomonas and anaerobes while the vancomycin covers MRSA. Choice E is an appropriate regimen with linezolid adequately providing MRSA coverage and piperacillin‐tazobactam providing coverage against anaerobes and Pseudomonas. Further treatment with antibiotics can be tailored to the patient based on culture and sensitivity data, and it is recommended that antibiotic treatment continue for at least two weeks following defervescence and source control of the empyema.Answer: AShen KR, Bribriesco A, Crabtree T, et al. The American Association for Thoracic Surgery consensus guidelines for the management of empyema. J Thorac Cardiovasc Surg. 2017; 153(6):e129–e146. doi:10.1016/j.jtcvs.2017.01.030Rosenstengel A . Pleural infection‐current diagnosis and management. J Thorac Dis. 2012; 4(2):186–193. doi:10.3978/j.issn.2072‐1439.2012.01.12Thys JP, Vanderhoeft P, Herchuelz A, et al. Penetration of aminoglycosides in uninfected pleural exudates and in pleural empyemas. Chest. 1988; 93(3):530–532. doi:10.1378/chest.93.3.530

6 A 56‐year‐old woman with asthma, who works in a long‐term healthcare facility, presents with fevers, chills, generalized myalgias, and a severe cough for the past four days. Over the last 24 hours, she has become significantly more short of breath. Her rapid influenza is positive, and her respiratory status continues to deteriorate. Chest x‐ray demonstrates a left lower lobe consolidation. She is admitted to the ICU. What should her treatment regimen include?Oseltamivir, vancomycin, piperacillin‐tazobactam, corticosteroidsOseltamivir, ampicillin‐sulbactam, and corti‐ costeroidsVancomycin and piperacillin‐tazobactamOseltamivir, vancomycin, and piperacillin‐ tazobactamOseltamivir and daptomycinThis patient may have coinfection with influenza and community‐acquired pneumonia. In patients who test positive for influenza and are admitted to the hospital, anti‐influenza treatment should be started, regardless of the duration of the illness before diagnosis. If this were a different patient who was being treated as an outpatient, administration of anti‐viral therapy is only recommended within two days of symptom onset. Given the patient’s employment in a long‐term‐care facility, she is at risk for MRSA, so initial coverage should be broad and cover MRSA as well as gram negatives. Daptomycin should not be used as it is inactivated by surfactant (choice E). Corticosteroids are not routinely prescribed for adults with severe CAP (choice A, B). Overall, the data for treatment with corticosteroids is conflicting with some showing a benefit and others showing no significant difference in outcomes. A meta‐analysis of pneumonia due to influenza based on small studies, however, showed an increase in mortality in patients who receive corticosteroids. Corticosteroids are recommended to be used in patients with refractory septic shock. IDSA guidelines removed the term “healthcare‐associated pneumonia (HCAP)” in 2016 and recommend that pneumonia be categorized as hospital acquired, community acquired, or ventilator associated. This patient has community‐acquired pneumonia as she did not develop the pneumonia after being admitted to the hospital. She does, however, have risk factors for MRSA and Pseudomonas infection due to her job at a long‐term healthcare facility. Because of this, she needs to be covered appropriately for MRSA and Pseudomonas infections.Answer: DMetlay JP, Waterer GW, Long AC, et al. Diagnosis and treatment of adults with community‐acquired pneumonia. Am J Respir Crit Care Med. 2019; 200(7):E45–E67. doi:10.1164/rccm.201908‐1581STUyeki TM, Bernstein HH, Bradley JS, et al. Clinical Practice Guidelines by the Infectious Diseases Society of America: 2018 Update on Diagnosis, Treatment, Chemoprophylaxis, and Institutional Outbreak Management of Seasonal Influenza. Clin Infect Dis. 2019; 68(6):895–902. doi:10.1093/cid/ciy874Davis BM, Aiello AE, Dawid S, et al. Influenza and community‐acquired pneumonia interactions: the impact of order and time of infection on population patterns. Am J Epidemiol. 2012; 175(5):363–367. doi:10.1093/aje/kwr402Silverman JA, Mortin LI, VanPraagh ADG, et al. Inhibition of daptomycin by pulmonary surfactant: in vitro modeling and clinical impact. J Infect Dis. 2005; 191(12):2149–2152. doi:10.1086/430352

7 A 58‐year‐old man presents to the hospital with left lower quadrant pain for 3 days, subjective fevers at home, and anorexia. He reports that he has been having frequent liquid stools. His vital signs are normal except for his temperature of 100.4°F. He is tender to palpation in his left lower quadrant of his abdomen. He has a leukocytosis of 18 × 103 cells/mm 3 with 80% neutrophils. A CT of his abdomen shows a 6 cm rim‐enhancing fluid collection and dots of free air in his pelvis. His most recent colonoscopy was 9 months ago and showed diverticulosis with no polyps or masses. The next best step in the management of this patient should be:Repeat colonoscopySurgical drainage of the fluid collectionPercutaneous drainage of the fluid collectionPICC line placement for fluid resuscitationSigmoidectomy and primary anastomosisThis patient has Hinchey II diverticulitis with a pelvic abscess. Proper management is percutaneous drainage if amenable and initiation of a fluoroquinolone or cephalosporin and metronidazole. Initiation of broad‐spectrum antibiotics, such as meropenem, should be reserved for patients with severe intra‐abdominal infection or for healthcare‐acquired intra‐abdominal infection. A PICC line is not necessary in this patient as the duration of antibiotics following source control with percutaneous drainage should be four days and there is no need for parenteral nutrition at this point in time. A repeat colonoscopy would not be appropriate at this time and would likely further injure the diseased bowel. He will need a colonoscopy to rule out malignancy 6 to 8 weeks after resolution of his disease. Surgical drainage is an option for obtaining source control but is significantly more invasive than a percutaneous drain. Similarly, choice E is incorrect and sigmoidectomy in this patient should be reserved for disease refractory to treatment. Antibiotic choices for this patient should cover gram‐negative aerobic and facultative bacilli as well as gram‐positive streptococci. This is a community‐acquired intra‐abdominal infection, and there is no need to initiate anti‐pseudomonal treatment in this patient. Ticarcillin‐clavulanate, cefoxitin, ertapenem, or moxifloxacin are adequate single‐agent choices. Treatment can also be dual agent with metronidazole in combination with cefazolin, cefuroxime, ceftriaxone, cefotaxime, levofloxacin, or ciprofloxacin. This patient’s initial antibiotic regimen should be given intravenously; however, if he progresses to tolerating adequate nutrition by mouth, it is reasonable to convert the therapy to an oral antibiotic for the duration of the treatment.Modified Hinchey classificationStageDefinition0Mild diverticulitisIaPericolonic phlegmon/inflammationIbPericolic abscessIIPelvic/retroperitoneal/distant abscessIIIPurulent peritonitisIVFecal peritonitisAnswer: CSolomkin JS, Mazuski JE, Bradley JS, et al. Diagnosis and management of complicated intra‐abdominal infection in adults and children: guidelines by the Surgical Infection Society and the Infectious Diseases Society of America. Clin Infect Dis. 2010; 50(2):133–164. doi:10.1086/649554Sawyer RG, Claridge JA, Nathens AB, et al. Trial of short‐course antimicrobial therapy for intraabdominal infection. N Engl J Med. 2015; 372(21):1996–2005. doi:10.1056/nejmoa1411162

8 A 36‐year‐old man was in MVC, and his injuries include large areas of desquamation with dirt and vegetation over the wounds and multiple open fractures. He is taken to the operating room for a positive FAST in the setting of hypotension. He undergoes an exploratory laparotomy and splenectomy as well as external fixation of his open femur fractures with wound washout. On post‐operative day 5, he becomes febrile and areas of his wound are noted to be black and necrotic. A biopsy is sent for histologic examination and returns mold with irregular non‐septate broad hyphae. What is the best treatment course for this patient?PosaconazoleAmphotericin BLipid formulation of amphotericin B and perform serial wound debridementsPosaconazole and perform serial wound debridementsMicafungin and perform serial wound debridementsThis patient has an invasive fungal infection with Mucor, which has irregular non‐septate broad hyphae. While rare, severely injured trauma patients can suffer from an invasive fungal infection. Mortality from this infection can be very high, so prompt debridement and antifungal therapy are important for success. Lipid formulation of amphotericin B (LAmB) is the antifungal of choice. LAmB has been shown to be more effective than other antifungals at treating Mucor, and the liposomal formulation has increased survivorship in patients with Mucor infections significantly (39%–67%). Other antifungals such as iatroconazole, voriconazole, and fluconazole do not have much effect against Mucor. Posaconazole has to be given in high and potentially toxic doses to treat Mucor and is not recommended as a first line option. It is, however, available to be used for refractory disease or for salvage therapy.Choice A is incorrect as Posaconazole is not the first line treatment for Mucor, and it can be used if needed in refractory disease.Choice B is incorrect as traditional formulations of amphotericin B have been shown to be significantly less effective against Mucor infections but it also lacks surgical debridement of the wound that plays a critical role in the treatment of the disease.Choice D is incorrect as Posaconazole is not a first line treatment for this disease.Choice E is incorrect as there is no data to suggest that micafungin is effective against Mucor.Answer: CSpellberg B, Ibrahim AS . Recent advances in the treatment of mucormycosis. Curr Infect Dis Rep. 2010; 12(6):423–9. doi: 10.1007/s11908‐010‐0129‐9. PMID: 21308550; PMCID: PMC2947016.Kronen R, Liang SY, Bochicchio G, et al. Invasive fungal infections secondary to traumatic injury. Int J Infect Dis. 2017; 62:102–111. doi:10.1016/j.ijid.2017.07.002Ganesan A, Shaikh F, Bradley W, et al. Classification of trauma‐associated invasive fungal infections to support wound treatment decisions. Emerg Infect Dis. 2019; 25(9):1639–1647. doi:10.3201/eid2509.190168Wilson W, Ali‐Osman F, Sucher J, et al. Invasive fungal wound infection in an otherwise healthy trauma patient (Mucor Trauma). Trauma Case Reports. 2019; 24:100251. doi:10.1016/j.tcr.2019.100251

9 A 24‐year‐old man sustained multiple gunshot wounds to the abdomen. He was taken to the OR, given a dose of cefoxitin, and underwent an exploratory laparotomy. He was found to have multiple small bowel injuries and a colon injury, both of which had caused spillage of bowel content. The most appropriate duration of antibiotic therapy in this scenario should be:No more than 24 hours48 hours4 days7 days14 daysThe duration of antimicrobial therapy is controversial, but most studies have found that there is no difference in infection rates between a 24‐hour course and a longer duration of therapy in patients that had penetrating abdominal trauma. Regardless, all patients with penetrating abdominal trauma should at least receive a single preoperative dose of broad‐spectrum antibiotics. Traditionally, the most effective time to provide antibiotic dosing is prior to the time of bacterial contamination, but since this is not possible with abdominal trauma, it is recommended that the dose be given as soon as possible. Appropriate antibiotics for a patient with penetrating trauma will be broad spectrum with aerobic and anaerobic coverage. Second‐generation cephalosporins are the recommended initial choice, and third‐generation cephalosporins can be used as an alternative. It is important to also note that in patients with penetrating abdominal trauma who are also in hemorrhagic shock will need additional dosing of antibiotics with repeated dosing after 10 units of blood transfused.Answer: AGoldberg SR, Anand RJ, Como JJ, et al. Prophylactic antibiotic use in penetrating abdominal trauma. J Trauma Acute Care Surg. 2012; 73(5 SUPPL.4):S321–S325. doi:10.1097/TA.0b013e3182701902Jang JY, Kang WS, Keum MA, et al. Antibiotic use in patients with abdominal injuries: guideline by the Korean Society of Acute Care Surgery. Ann Surg Treat Res. 2019; 96(1):1–7. doi:10.4174/astr.2019.96.1.1Hospenthal DR, Murray CK, Andersen RC, et al. Guidelines for the prevention of infections associated with combat‐related injuries: 2011 update: endorsed by the Infectious Diseases Society of America and the Surgical Infection Society. J Trauma. 2011; 71(2 Suppl 2):S210–S234.Rhodes A, Evans LE, Alhazzani W, et al. Surviving sepsis campaign. Crit Care Med. 2017; 45(3):486–552. doi:10.1097/CCM.0000000000002255Gordon AC, Mason AJ, Thirunavukkarasu N, et al. Effect of early vasopressin vs norepinephrine on kidney failure in patients with septic shock: the VANISH randomized clinical trial. JAMA ‐ J Am Med Assoc. 2016; 316(5):509–518. doi:10.1001/jama.2016.10485Russell JA, Walley KR, Singer J, et al. Vasopressin versus norepinephrine infusion in patients with septic shock. N Engl J Med. 2008; 358(9):877–887. doi:10.1056/nejmoa067373Demiselle J, Fage N, Radermacher P, Asfar P . Vasopressin and its analogues in shock states: a review. Ann Intensive Care. 2020; 10(1):9. doi:10.1186/s13613‐020‐0628‐2

10 A 68‐year‐old woman with diabetes, coronary artery disease, and peripheral vascular disease presents to the hospital 21 days after an emergent fem‐femoral bypass. She is febrile and tachycardic with a white count of 16 × 103/microL. Her right groin incision is open with visible pus, and the area over the graft is erythematous and tender. A CTA shows increased soft tissue inflammation around the graft. What is the next best step?Obtain an ultrasound to assess blood flow velocities.Start intravenous ceftriaxone and flagyl.Start oral cephalexin.Explant the graft and replace with autologous vein.Start intravenous vancomycin and piperacillin‐ tazobactam.This patient has a graft infection. Gram‐positive bacteria are the most causative organisms. Typically, the rate of vascular graft infection is 1.5–2.5%, but the infection rate of grafts in the groin can be as high as 6%. Not only does this patient have grafts in the bilateral groins, but her diabetes and the urgent nature of her initial procedure also increases her risk of graft infection.While Staphylococcus aureus is the most common cause of vascular graft infection, there has been a documented rise of MRSA isolates from infected grafts as well as Pseudomonas aeruginosa, which is about 10% of graft infections. Because of this, a patient with a vascular graft infection should initially receive broad‐spectrum antibiotic coverage extended to cover Pseudomonas and MRSA. Of the choices, only choice E (vancomycin and piperacillin‐tazobactam) provides appropriate antibiotic coverage for this patient.Ceftriaxone, metronidazole, and cephalexin do not cover MRSA. While obtaining an ultrasound can help assess blood flow, a CTA is 85–100% sensitive and 85–94% specific for graft infection and can be obtained quickly. There are some scenarios of surgical site infection after a vascular graft in which antibiotics, debridement, and wound care can be used to preserve an infected graft, and the graft will first need to be surgically explored before the decision for preservation or explant is made. If the decision is made to preserve the graft, a prolonged course of antibiotics will be required.Answer: ESpelman D . Overview of infected (mycotic) arterial aneurysm ‐ UpToDate. UpToDate. https://www.uptodate.com/contents/overview‐of‐infected‐mycotic‐arterial‐aneurysm?search=infected vascular graft&source=search_result&selectedTitle=1~20&usage_type=default&display_rank=1#H1118621. Published July 2019. (accessed 3 December 2020).Chakfé N, Diener H, Lejay A, et al. Editor’s Choice – European Society for Vascular Surgery (ESVS) 2020 clinical practice guidelines on the management of vascular graft and endograft infections. Eur J Vasc Endovasc Surg. 2020; 59(3):339–384. doi:10.1016/j.ejvs.2019.10.016Kilic A, Arnaoutakis DJ, Reifsnyder T, et al. Management of infected vascular grafts. Vasc Med (United Kingdom). 2016; 21(1):53–60. doi:10.1177/1358863X15612574Wilson WR, Bower TC, Creager MA, et al. American Heart Association Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease of the Council on Cardiovascular Disease in the Young; Council on Cardiovascular and Stroke Nursing; Council on Cardiovascular Radiology and Intervention; Council on Cardiovascular Surgery and Anesthesia; Council on Peripheral Vascular Disease; and Stroke Council. Vascular Graft Infections, Mycotic Aneurysms, and Endovascular Infections: A Scientific Statement from the American Heart Association. Circulation. 2016; 134(20): e412–e460. doi: 10.1161/CIR.0000000000000457. Epub 2016 Oct 13. PMID: 27737955.

11 A 53‐year‐old man is in the ICU after a severe MVC. He has been on the ventilator for six days due to respiratory failure and lung contusion. He is noted to have increased inspiratory pressures, worsening hypoxemia, and purulent secretions. He has a white count of 16 × 103/microL and a progressive infiltrate on his chest x‐ray. What is the appropriate duration of antibiotics to treat his ventilator‐associated pneumonia?3 days5 days7 days10 days14 daysMultiple studies have shown that short‐course antibiotic regimens (7–8 days) increased the antibiotic‐free days; when compared to longer duration of antibiotics (10–15 days), there was also no difference in mortality, duration of mechanical ventilation, or length of ICU stay. In turn, reducing antibiotic exposure reduces side effects, antibiotic resistance, and costs.In patients with VAP, it is recommended that coverage includes S. aureus, P. aeruginosa, and gram‐negative bacilli. Empiric treatment of MRSA and Pseudomonas should be employed if the patient has recent risk factors for drug‐resistant infection including prior IV antibiotics use within 90 days, current septic shock, ARDS preceding the VAP, more than 5 hospital days preceding VAP diagnosis, and acute renal replacement therapy prior to the VAP onset. If the patient received IV antibiotics within the past 90 days, it is recommend that they be prescribed two agents that cover Pseudomonas in addition to an agent that covers MRSA.Answer: CZilahi G, McMahon MA, Povoa P, et al. Duration of antibiotic therapy in the intensive care unit. J Thorac Dis. 2016; 8(12):3774–3780. doi:10.21037/jtd.2016.12.89Kalil AC, Metersky ML, Klompas M, et al. Management of adults with hospital‐acquired and ventilator‐associated pneumonia: 2016 clinical practice guidelines by the Infectious Diseases Society of America and the American Thoracic Society. Clin Infect Dis. 2016; 63(5):e61–e111. doi:10.1093/cid/ciw353Torres A, Niederman MS, Chastre J, et al. International ERS/ESICM/ESCMID/ALAT guidelines for the management of hospital‐acquired pneumonia and ventilator‐associated pneumonia. Eur Respir J. 2017; 50(3). doi:10.1183/13993003.00582‐2017

12 An 83‐year‐old man with COPD, diabetes, and renal failure underwent resection of necrotic bowel from a closed‐loop small bowel obstruction. He remains mechanically ventilated. On post‐operative day six, he developed a fever to 102°F and a leukocytosis. A new right lobe infiltrate is seen on chest x‐ray, and he is diagnosed with ventilator‐associated pneumonia. Culture results are positive for Acinetobacter. What is the appropriate treatment?Piperacillin‐tazobactam and gentamicinVancomycinColistinMeropenemCiprofloxacinAcinetobacter is a gram‐negative bacilli that is a common cause of late‐onset VAP. Acinetobacter species are sensitive to carbapenems, ampicillin‐sulbactam, and colistin. Carbapenems and ampicillin‐sulbactam are preferred to colistin due to the risk of nephrotoxicity with colistin. Vancomycin is ineffective. Historically, ciprofloxacin has been effective in treating Acinetobacter, but the rate of ciprofloxacin‐resistant Acinetobacter infections has been reported as high as 67% in recent years and is thus no longer considered an effective empiric treatment. Gentamicin is a viable treatment option for an Acinetobacter infection; however, the addition of piperacillin‐tazobactam in choice A is unnecessary to treat this infection.Answer: DKalil AC, Metersky ML, Klompas M, et al. Management of adults with hospital‐acquired and ventilator‐associated pneumonia: 2016 clinical practice guidelines by the Infectious Diseases Society of America and the American Thoracic Society. Clin Infect Dis. 2016; 63(5):e61–e111. doi:10.1093/cid/ciw353Wood GC, Hanes SO, Croce MA, et al. Comparison of ampicillin‐sulbactam and imipenem‐cilastatin for the treatment of Acinetobacter ventilator‐associated pneumonia. Clin Infect Dis. 2002; 34(11):1425–1430. doi:10.1086/340055

13 A 35‐year‐old man suffers a 50% total body surface area third‐degree burns after a house fire and has been in the burn ICU for the past 28 days. He has undergone multiple surgeries for his wounds and has been treated for a ventilator‐associated pneumonia and a central line infection. Overnight, he develops a fever to 103°F and increased tachycardia and hypotension. On the changing of his dressings in the morning, the wound care nurse notes a sweet smell and areas of his torso wound appear to have a blue‐green color. What is the appropriate treatment?Cefepime and ciprofloxacinPiperacillin‐tazobactamColistinVancomycinTobramycin and amikacinThis patient has an infected burn wound. Pseudomonas aeruginosa; the blue‐green color and sweet, grape smell are characteristic. This patient with his prolonged hospital stay and previously treated infections is at risk for multidrug‐resistant strains. Wound culture is important to obtain to determine susceptibility. For initial empiric therapy, while there is controversy in monotherapy versus combination therapy, combination therapy is used due to the high risk of drug resistance in Pseudomonas. In combination therapy, the goal is to use antibiotics with two different mechanisms of action (tobramycin and amikacin are both aminoglycosides and share the same mechanism of action, making this an inappropriate choice). Colistin, a polymyxin, should be preserved for serious infection with proven multidrug isolates. Vancomycin is not an appropriate choice since it does not cover Pseudomonas. While piperacillin‐tazobactam covers Pseudomonas, it is a single agent.Answer: ATraugott KA, Echevarria K, Maxwell P, et al. Monotherapy or combination therapy? The Pseudomonas aeruginosa conundrum. Pharmacotherapy. 2011; 31(6):598–608. doi:10.1592/phco.31.6.598Micek ST, Lloyd AE, Ritchie DJ, et al. Pseudomonas aeruginosa bloodstream infection: importance of appropriate initial antimicrobial treatment. Antimicrob Agents Chemother. 2005; 49(4):1306–1311. doi:10.1128/AAC.49.4.1306‐1311.2005Kang CI, Kim SH, Kim H Bin, et al. Pseudomonas aeruginosa bacteremia: risk factors for mortality and influence of delayed receipt of effective antimicrobial therapy on clinical outcome. Clin Infect Dis. 2003; 37(6):745–751. doi:10.1086/377200

14 A 47‐year‐old man with obesity and diabetes suffers a deep laceration to his left thigh while working on his farm. He presents one day after the injury with severe pain in his left thigh, spreading erythema, and bullae. Necrotic muscle is visible in the wound, and he has crepitus on exam. The patient is started on broad‐spectrum antibiotics and taken to the OR for debridement. Gram stains reveal a gram‐positive rod. What is the most appropriate antibiotic regimen?Vancomycin, piperacillin‐tazobactam, and clindamycinVancomycin and clindamycinPenicillin and clindamycinGentamycin and piperacillin‐tazobactamPenicillin and metronidazoleNecrotizing soft tissue infections (NSTIs) have high morbidity and mortality. The goal is prompt recognition, antibiotics, and surgical debridement. Initially, it is important to start the patient on broad‐spectrum antibiotics that include coverage for MRSA and anaerobes. Gram stains suggest infection with Clostridium species, which is a gram‐positive rod. For Clostridium myonecrosis, the Infectious Disease Society of America (IDSA) currently recommends starting penicillin and clindamycin. Treatment should continue for 10–14 days after source control. Choices A, B, and D do not include penicillin – the appropriate antibiotic for Clostridium. Choice E does not contain clindamycin, which helps prevent exotoxin release.Answer: CStevens DL, Bisno AL, Chambers HF, et al. Practice guidelines for the diagnosis and management of skin and soft tissue infections: 2014 update by the Infectious Diseases Society of America. Clin Infect Dis. 2014; 59(2):e10–e52. doi:10.1093/cid/ciu296Stevens DL, Bryant AE . Necrotizing soft‐tissue infections. Longo DL, ed. N Engl J Med. 2017; 377(23):2253–2265. doi:10.1056/NEJMra1600673

15 A 47‐year‐old woman who is eight months status post a deceased‐donor kidney transplant is admitted with nausea, vomiting, and watery diarrhea. She is tachycardic, afebrile, and normotensive with a leukopenia at 3 × 103/microL. Colon biopsies are positive for CMV. In addition to decreasing immunosuppression, which of the following should be started?Oral valganciclovirIV ganciclovirIV foscarnetOral ganciclovirOral oseltamivirCMV is a major cause of infection in solid‐organ transplant patients. The risk is highest in lung and small bowel transplant recipients. Biopsy is occasionally needed to confirm the presence of tissue‐invasive disease if nucleic acid testing is negative. CMV is treated by decreasing immunosuppressive medications and starting appropriate antiviral therapy. IV ganciclovir is the first line therapy for gastrointestinal CMV. Oral valganciclovir, while effective for CMV, will not be effectively absorbed in a patient with GI disease (Choice A). IV foscarnet is a second‐line therapy for treatment and is highly nephrotoxic (choice C). Oral ganciclovir and oseltamivir are not indicated in CMV infection. Oral ganciclovir should not be used for treating CMV disease as there is concern it may lead to emergence of ganciclovir resistance as its poor bioavailability leads to insufficient systemic levels. Oseltamivir is effective in treating influenza viruses, and there is no data to suggest that it would be an effective treatment for CMV infection.Answer: BRazonable RR, Humar A . Cytomegalovirus in solid organ transplantation. Am J Transplant. 2013; 13(SUPPL.4):93–106. doi:10.1111/ajt.12103Eid AJ, Arthurs SK, Deziel PJ, et al. Clinical predictors of relapse after treatment of primary gastrointestinal cytomegalovirus disease in solid organ transplant recipients. Am J Transplant. 2010; 10(1):157–161. doi:10.1111/j.1600‐6143.2009.02861.x

16 Which of the following practices is the least effective in reducing central line‐associated bloodstream infection (CLABSI)?Appropriate hand hygiene and skin preparationFollowing a checklist during line insertionDaily bathing of ICU patients with chlorhexidineRemoval of unnecessary linesChoosing the subclavian vein for a central line insertionCentral line‐associated bloodstream infection (CLABSI) is a frequent cause of hospital‐associated infection. A multimodal approach has been shown to be effective in decreasing CLABSI. Hand hygiene is the most important practice in reducing healthcare‐associated infections. Following a checklist during insertion ensures that steps, such as hand hygiene, skin preparation, and use of maximal sterile barrier precautions, should not be forgotten. The risk of developing a line infection increased with each day of use; reassessing their need daily helps remove a nidus for infection. The femoral site has the highest risk of infection followed by internal jugular and subclavian. Daily bathing of ICU patients with chlorhexidine did not demonstrate a reduction in CLABSIs, catheter‐associated urinary tract infections (CAUTIs), ventilator‐associated pneumonia, or Clostridium difficile in a randomized control trail.Answer: CMiller SE, Maragakis LL . Central line‐associated bloodstream infection prevention. Curr Opin Infect Dis. 2012; 25(4):412–422. doi:10.1097/QCO.0b013e328355e4daLatif A, Halim MS, Pronovost PJ . Eliminating infections in the ICU: CLABSI. Curr Infect Dis Rep. 2015; 17(7). doi:10.1007/s11908‐015‐0491‐8Noto MJ, Domenico HJ, Byrne DW, et al. Chlorhexidine bathing and health care‐associated infections: a randomized clinical trial. JAMA ‐ J Am Med Assoc. 2015; 313(4):369–378. doi:10.1001/jama.2014.18400

17 A 63‐year‐old female with type II diabetes and a recent HbA1c of 9.4 presents to the ED after she noted a foul odor emanating from the sole of her foot. Upon inspection of her foot, she noticed a large ulcer with surrounding erythema and purulence in the wound bed and presented to the ED. Upon evaluation in the ED, her WBC is 14.4 and she is afebrile. She denies being hospitalized or having a wound like this before.Next steps in care for this patient include:Immediate culture of wound, initiation of meropenem, MRI of the footImmediate culture of wound, initiation of vancomycin and piperacillin/tazobactam, MRI of the footCleansing and debridement of the wound followed by culture of the wound, initiation of ertapenem, MRI of the footCleansing and debridement of the wound followed by culture of the wound, initiation of ertapenem, x‐ray of the footImmediate initiation of vancomycin/piperacillin/tazobactam, debridement and culture of the wound, x‐ray of the foot. This patient has a diabetic foot infection and the wound should be evaluated and treated. Prior to antibiotic administration, the wound should be cleansed and debrided with the deep tissue from the wound sent for culture. Failure to do this can lead to the culturing of skin flora that may not be responsible for the infection. The wound should then be classified, and a probe‐to‐bone test can be used to help in making this decision. There are multiple ways to classify diabetic foot infections; two of the most frequently used classifications are mentioned below.Following an adequate culture and classification of the wound, an antibiotic regimen can be started. This wound would be classified as a moderate diabetic foot infection and therefore should be treated with antibiotics. In a moderate diabetic foot infection, aerobic GPCs, MSSA, Streptococcus spp., Enterobacteriaceae, and other obligate anaerobes are the likely pathogens. These are all adequately covered by ertapenem. Initiation of vancomycin and piperacillin/tazobactam would be a correct answer if this patient had a severe diabetic foot infection. She does not require any further coverage for MRSA or pseudomonal infections as she does not have any current risk factors, nor is her illness severe enough to prompt broad‐spectrum empiric antibiotic coverage.Initial imaging of a diabetic foot infection should always be an x‐ray of the foot, which is both sensitive and specific for osteomyelitis. If any diagnostic uncertainty remains following the x‐ray, an MRI can be pursued.Answer: DLipsky BA., Berendt AR, Cornia PB, et al. 2012 Infectious Diseases Society of America Clinical Practice Guideline for the Diagnosis and Treatment of Diabetic Foot Infections, Clin Infect Dis. 2012; 54 12: e132–e173, https://doi.org/10.1093/cid/cis346

18 A 67‐year‐old male who has returned 6 weeks ago from a trip to New England where he had been trail‐running in preparation from a marathon presents to the ED complaining of intractable fatigue, dark‐reddish urine, and frequent high fevers at home. He reveals that he had pulled a small bug off his arm during his trip and that he did not notice any associated rash. He has splenomegaly on physical exam. His labs return showing a normocytic anemia with elevated transaminases. A Wright’s/Giemsa stain of his peripheral blood demonstrates darkly stained rings with light blue cytoplasm within erythrocytes. The most likely disease responsible for his condition is:Lyme diseaseBabesiosisRocky Mountain Spotted FeverEhrlichiosisAnaplasmosisThis patient has babesiosis, more specifically an infection with the parasite Babesia microti. B. microti is an intraerythrocytic parasite that is transmitted from ticks to vertebrates including humans. The disease contracted by the host can be broad with varying symptoms ranging from asymptomatic infection to a disease like malaria with severe hemolysis and death. Symptoms can take months after exposure to develop. Common signs and symptoms of babesiosis are fatigue, anemia, fevers, chills, night sweats, hemoglobinuria, transaminitis, weight loss, hepato/splenomegaly. Diagnosis is typically made with exposure to ticks, stained blood smears, and ELISA/PCR. The standard treatment for babesiosis is clindamycin and quinine. In a serious infection where clindamycin and quinine are not sufficient, there has been some benefit shown in erythrocyte exchange transfusion.Lyme disease is the most common tick‐borne illness in the United States and is also hosted by the Ixodes tick. It is known for its characteristic bull’s‐eye rash (erythema migrans), but this is not present in all cases. Lyme disease commonly presents with low‐grade fevers and myalgias. The disease, however, can disseminate and affect the musculoskeletal, neurologic, and cardiovascular system. Most commonly, musculoskeletal symptoms are present in Lyme disease in the form of migratory joint and muscle pain. Anemia is not associated with Lyme disease, and this spirochete bacterium is not apparent on a peripheral blood smear. Treatment for Lyme disease is typically doxycycline for adults and amoxicillin for children.Rocky Mountain Spotted Fever is a serious disease that is caused by Rickettsia rickettsii and transmitted after a tick bite. It is most common in the southeastern and south‐central United States. This bacterium preferentially infects the vascular endothelial cells of small and medium vessels in the body. Patients typically present 4–10 days post exposure and have fever, headache, and a rash. Typically, patients are treated empirically based on their history and physical with doxycycline, but PCR can be performed to confirm diagnosis.Ehrlichiosis is a tick‐borne disease carried by the Lone Star Tick found in the south‐central United States. Ehrlichiosis is associated with fever, headache, body aches, malaise, and chills but can include gastrointestinal symptoms, respiratory symptoms, and rash. Associated laboratory findings include leukopenia, thrombocytopenia, hyponatremia, and moderately elevated transaminases. Diagnosis is made clinically or by PCR. Treatment is doxycycline.Anaplasmosis is transmitted by the Ixodes tick and is found worldwide; it is caused by Anaplasma phagocytophilum – an obligate intracellular bacterium. Symptoms include fever, malaise, myalgias, and headache with some patients experiencing nausea, vomiting, diarrhea, cough, arthralgias, and confusion. Rash is uncommon in anaplasmosis. Anaplasmosis is visible on peripheral blood smear, and it can be seen within the neutrophils in aggregates called morulae. Doxycycline is the first line treatment for anaplasmosis.Answer: BGuzman N, Yarrarapu SNS, Beidas SO. . Anaplasma Phagocytophilum. [Updated 2021 Jan 5]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021. Available from: https://www.ncbi.nlm.nih.gov/books/NBK513341/Homer MJ, Aguilar‐Delfin I, Telford SR III, et al. Babesiosis. Clin Microbiol Rev. 2000; 13(3):451–69. doi: 10.1128/cmr.13.3.451‐469.2000. PMID: 10885987; PMCID: PMC88943.Snowden J, Simonsen KA, Rickettsiae Rickettsia. [Updated 2020 Nov 20]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021. Available from: https://www.ncbi.nlm.nih.gov/books/NBK430881/Snowden J, Bartman M, Kong EL, et al. Ehrlichiosis. [Updated 2020 Sep 17]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021. Available from: https://www.ncbi.nlm.nih.gov/books/NBK441966/Bratton RL, Whiteside JW, Hovan MJ, et al. Diagnosis and treatment of Lyme disease. Mayo Clin Proc. 2008; 83(5):566–71. doi: 10.4065/83.5.566. PMID: 18452688